Searching for new physics in WW and single-W events

TL;DR

This paper discusses the potential for discovering new physics through precision measurements of W boson production at future colliders, using full simulations to project significant improvements over past experiments.

Contribution

It presents simulation-based projections for enhanced measurements of triple-gauge couplings and CKM matrix elements at future electron-positron colliders, advancing the precision frontier.

Findings

Projected one to two orders of magnitude improvement in measurement precision.

Demonstrated the potential of full simulation for future collider studies.

Highlighted the complementarity of W boson measurements to B hadron decay studies.

Abstract

Pair-production and single-production of $W$ bosons provide many opportunities to look for new physics via precision measurements, for instance via scrutinising the involved triple-gauge vertices or by measuring CKM matrix elements in an environment very complementary to $B$ hadron decays. This contribution presents the ongoing work based on full simulation of the ILD concept, exploiting the O($10^8$) $W$ bosons produced during the $250$\,GeV stage of the ILC, as well as the CLD concept proposed for the FCC-ee. The projections, which also contribute to two focus topics of the current ECFA study on future Higgs/Top/Electroweak factories, promise improvements of the measurement precision of TGCs and the CKM matrix, respectively, of one to two orders of magnitude with respects to LEP.